I want to make a spiral in a sphere shape that has endpoints which are close together
Destructively: apply all modifiers and scale in one of the object's axes.  (Alt c convert to-&gt;mesh is a quick way to apply all modifiers.)
Non-destructively 1: Create an empty at the center of your sphere.  Designate this empty as the &quot;object&quot; for your Cast modifier.  Check &quot;Use transform&quot; on the modifier.  Scale this empty in one of its axes.
Non-destructively 2: create a single bone armature, weight your vertex (lol) to the bone, and use an armature modifier.  While armatures are typically thought of as animation tools, they can easily be used as modelling tools to create non-destructive, arbitrary transformations.  (Animation is just modelling over time, after all.)
Destructive (left) vs non-destructive 2 (right):

In that pic, I've placed the armature modifier above the solidify modifier, which keeps your proportions nicer than the leftmost cube (demoing the destructive option above, although you can be slightly less destructive to achieve the same mesh as on the right.)